Nut setter



Mach 99 w43 P. VAN snTTERT ET AL '2,313,503

NUT SETTER Filed Dec. 12, 1941 'I 2//5 /y/ .A

22 i l I INVENTORS ATORNEY Patented Mar. 9, 1943 NUT SETTER Paul Van Sittert, Shaker Heights, and Andrew J. Lev, Garfield Heights, Ohio, assignors to The Cleveland Pneumatic Tool Company, Cleveland, Ohio, a corporation of Ohio Application December 12, 1941, .Serial No. 422,711

4 Claims. (Cl. 192 30.5)

This invention relates to nut setters, that is t say, power tools for turning down and tightening nuts or the like. More particularly, the invention covers a tool of this character which operates by intermittent impact after the resistance they are adapted to be engaged by by the clutch dogs I3 on plate I2, and thus to establish positive driving connections from the motor to the flywheel.

The clutch bars 22 constitute the only means to rotation of the driven memberreaches a prei" for rotatably connecting the flywheel with the determined value. driven member, but as between the driver and One of the objects of the invention is the prothe flywheel, there is in addition to the positive ViSOn 0f a tool in which impacts are transmitted drive connection above described, a frictionconto the Work from a flywheel which has a fricl nection which tends to rotate the iiywheel whention connection only with the motor at the times ever the drive shaft II rotates, but which yields when the impacts are delivered. or slips when the load reaches a predetermined Another object is the provision of means for minimum. To this end we provide an annular positively clutching a flywheel to the driving and disk 25 having diametrically opposed projections driven members alternately, said means affording 15.l 26 which extend into the slots 2l so that the disk ample opportunity for the flywheel to gain mo- 25 must always turn with the flywheel. Friction mentum between the delivery of impacts. ,rings 21 and 2S are riveted or otherwise secured Other objects and features of novelty will apto disk 25, ring 2l bearing against a surface of pear as we proceed with the description of that plate I2 and ring 28 bearing against a metal ring embodiment of the invention which, for the pur- 2a 29 which is slidable upon shaft l I but prevented poses of the present application, we have illusfrom turning relative to the shaft by keys 3l). trated in the accompanying drawing, in which: Disk 25 with its friction rings 2l and 28 is con- Fig. 1 is a fragmental view, principally in cenfined between plate I2 and ring 29, a coil spring tral longitudinal section, of a power tool embody- 3l being employed to force these parts together ing the invention; 25 and the degree of friction exerted being con- Figs. 2 and 3 are detail sectional views corretrolled by a ring 32 which is threaded onto shaft spending to a portion of Fig. l, showing one of II. i the pivoted clutch bars in positions different fromY Surrounding shaft I5 and rotatable with rethat of Fig'. l; and spect to that shaft, as well as with respect to the Figs. 4, 5, 6, 7, and 8 are cross-sectional views 3Q, flywheel 20, there is a sleeve 33 which includes on a smaller scale taken substantially on the integral cams 34 and 35. These two cams are lines 4 4, 5 5, 6 6, 1 1, and 8 8 of Fig. 1. identical in form and size but are spaced angu- Referring particularly to Fig. l of the drawlarly 90 apart. Two pairs of pins 36 and 3l ing, a portion of the housing of the nut setter positioned in radial bores in the flywheel engage is shown at I0. This housing also encloses a 35 the cams 34 and 35 and by them are slidable in motor, not shown, having a shaft I I terminating and out, one pair in opposition to the other. The in a plate I2 that is provided at diametrically opouter ends of these pins are rounded and engage posite points with a pair of outwardly protrudthe two clutch bars 22 upon opposite sides of ing clutch dogs I3. The plate I2 and shaftl I I their pivots 23. By this means the bars 22 are are recessed axially to receive rotatably the conswung from one operative position to the other. stricted end I4 of a shaft I5 which projects from Sleeve 33 at its inner end beyond cam 34 is a second plate I6 that is also provided with a formed as a Geneva movement Wheel 40, the rapair of diametrically opposed outwardly projectdial slots of which are adapted to be engaged by ing Clutch dogs l'! similar t0 thev dogs I3. Plate pins 4| and 42 Carried by a, gear 43, The latter I5 iS C21-Tried by a Shaft I3 J`0lll^na1ed in 2L bllSh- 415. gear also carries a locking element 44 of familiar ing IS 'that iS mOlmted in housing I0, the shaft form cooperating with the wheel 46 to hold it I8 and the plaie I5 constituting the driven memagainst relative rotation except at times when ber of the tool to which a socket wrench, not one of the pins is in engagement with a slot of the Shf-Wv'fl, may be connected. wheel. Gear 43 turns upon a short shaft 45 A generally cylindrical ywheel 20 is provided 50 which is xed in plate l2, and meshes with a at its ends With recesses in which the plates I2 pinion 46 cui; in shaft I4. and I5 ae IOCatd- At ODDOSS DOHS thS y- Operation. Assuming that the parts are in wheel is slotted longitudinally, and in the slots 2I the positions illustrated in Fig. l and that the a pair of clutch bars 22 are pivotally mounted on tool is held in position to drive a nut, when the pins 23. When these clutch bars are swung to operator starts the motor which turns driving the position illustrated in Fig. 1, they are adapted member II I2 in clockwise direction in Fig. 4, to engage the clutch dogs Il on plate I6 and to rotation is imparted through disk 25 and projecimpart rotary movement from the flywheel to the tions 26 to the flywheel 2li, and from the iiydriven member. On the other hand when the wheel through the clutch bars 22 to plate I6 and clutch bars are swung to the position of Fig. 3, the driven member I8.

If, when the power is turned on, the clutch bars 22 happen to be in the position illustrated in Fig. 3, motion is transmitted to the then free iiywheel not only by the friction connection, but also positively through the clutch dogs I3 and the clutch bars 22. Gear 43 revolves, running upon pinion 46, which will cause the Geneva movement to function in a manner presently to be described to throw the clutch bars to the position of Fig. l, whereupon drive through the friction connection to the flywheel and thence between dogs I'I and clutch bars 22 to the plate I6 and shaft I8 will take place.

All of the parts will then rotate as a unit, continuing until the resistance to rotation set up by the nut as it is tightened on the bolt reaches a predetermined value, when the shaft IB--I will stand still. The flywheel likewise will stand still and the friction plate 25 with its rings 2T and 28 will slip between the plate I2 and the ring 29. Shaft II continuing to rotate in clockwise direction in Fig. 4 will cause the gear 43 to turn upon the then stationary pinion 46 in the same direction as the shaft I I, that is, in counterclockwise direction in Fig. 5, while the Geneva wheel which is integral with the sleeve 33 will be locked against rotation by the rotating locking element 44, thereby maintaining the wheel in proper position to receive one of the pins carried by the gear 43. As the gear 43 continues its rotation in counterclockwise direction in Fig. 5, the pin 42 will move into the adjacent slot of the Geneva wheel 43 to rotate the latter 90, the locking element 44 being now positioned with one of its concaved portions above the wheel to enable rotation of the wheel. The 90 rotation of the Geneva wheel is of course transmitted to the sleeve 33 and results in the rotation of the cams 34 and 35 to reverse their relative positions, causing the pins 3B and 31 to swing the bars 22 from their Fig. 1 position through their Fig. 2 position to their Fig. 3 position, As soon as the Fig. 2 position is reached and the flywheel is freed from the driven member, slippage in the friction drive will decrease. The bars 22 will be in position to engage dogs I3 on clutch plate I2, but by the time this occurs, the iiywheel will have picked up some speed and the shock of bars 22 engaging dogs I3 will be lessened.

Shaft II and flywheel 20 will now rotate together. The gear ratio between pinion 46 and gear 43 is calculated to enable the shaft II and the plate I2 to revolve about three times before the pin 4I engages one of the slots of the Geneva wheel 4B. During this relative rotation, the Geneva wheel is locked against accidental rotation by the largest conveXed portion of the locking element 44 engaging the wheel. As the pin 4I enters one of the slots of the Geneva Wheel, it will turn the wheel as well as the sleeve 33 through another 90 angle with respect to the flywheel. When this occurs, the cams 34 and 35 and the pins 36 and 3I will again tilt the clutch bars 22 to the Fig. l position, freeing the flywheel from the driving member and causing it to deliver a rotary impact to the driven member. As soon as this occurs, the flywheel stops while the shaft II and gear 43 continue to rotate. Due to the relatively small angle between the pins 4I and 42, the pin 42 will again enter one of the slots of the Geneva wheel after a relatively short period of rotation of the shaft II with respect to the flywheel, causing the Geneva wheel and sleeve 33 to rotate 90 for again tilting the clutch bars 22 to the Fig. 3 position and starting a new cycle. -Inthis manner a series of rotary impacts are delivered to the driven member and the nut which is being driven is tightened down securely upon its bolt.

The fact that the motor shaft and the flywheel are permitted to continue in driving relation through several revolutions, thereby enabling the flywheel to gain considerable momentum while the flywheel and driven member remain in operative relation long enough only to transmit an impact, constitutes an important feature of the invention.

As will be obvious, the tool is so designed that by reversing the motor, a nut may be unthreaded. In such a case, however, the series of impacts will be delivered as the first part of the operation and continuous rotation will begin after the nut is sufficiently loosened.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

Having thus described our invention, we claim:

1. In a nut setter, a driver, a iiywheel, a driven member, means for clutching together the driver and flywheel or the driven member and fiywheel alternately, cam means for shifting said clutching means from one operative position to the other, and means comprising a Geneva movement operated by relative rotation of the driver and driven member for turning said cam means intermittently.

2. In a nut setter, a driver, a flywheel, a driven member, means for clutching together the driver and flywheel or the driven member and flywheel alternately, cam means for shifting said clutching means from one operative position to the other, gearing connections operated by relative rotation of the driver and driven member for rotating said cam means relatively to said flywheel at spaced instants and locking the cam means and flywheel against relative rotation during the interval between said instants.

3. In a nut setter, a driver, a flywheel, a driven member, means for clutching together the driver and flywheel or the driven member and flywheel alternately, cam means for shifting said clutching means from one operative position to the other, and means comprising a Geneva movement operated by relative rotation of the driver and driven member for turning said cam means intermittently, said means being arranged to maintain the driver and flywheel in engagement longer than the flywheel and driven member.

4. In a nut setter, a driver, a flywheel, a driven member coaxial with the driver and flywheel, a clutch bar pivotally mounted in the flywheel and extending beyond both ends thereof, said clutch bar being shiftable on its pivot to clutch together the driver and flywheel or the ywheel and driven member alternately, rotary cam means for shifting said clutch bar, and means functioning in response to relative rotation of the driver and driven member for turning said cam means to effect shifting of said clutch bar.

PAUL VAN SITTERT. ANDREW J. LEV. 

